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49-905 IF Transformer disassembly question
OZ4
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Posts: 285
Threads: 27
Joined: Nov 2012
City: Tehachapi. California
#11

11-03-2014, 02:00 PM
Back to this one again. So I have done the basics and replaced bad tubes no more hum. Now the radio works kinda. Even the fm works with poor sensitivity. 

The question I have is on IF transformer Z302. The signal level is dropping from 4vpp to .04vpp through it yet it seems to tune OK. (measured with a X10 scope probe) From the drawings Z302 looks like it is a step up transformer.

The other IF transformer has a drop from 4vpp to .5vpp.

 Am I missing something here?
http://www.nostalgiaair.org/PagesByModel...013674.pdf

Upon further inspection and a different method of measuring I found that Z302 the input side has 4vpp and the output also has 4vpp.

I am still stumped as why there is such poor am reception. It seem there is not enough gain. and I don't know what is normal for this thing. I am tired of it for now I will work on it some more later.

Thats all for now.
Chris
!!!!!!!!!!!!!!!!!!!RESISTANCE IS FUTILE!!!!!!!!!!!!!!!!!!!!!!  
                           /\/\/\/\/\/\/\/\/\
                                                     
                                 [Image: http://philcoradio.com/phorum/images/smi...on_eek.gif]  Chris
(This post was last modified: 11-03-2014, 08:03 PM by OZ4.)
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RE: 49-905 IF Transformer disassembly question - by OZ4 - 11-03-2014, 02:00 PM



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